1. Field of the Invention
The present invention relates to a dielectric heating system of a dielectric material such as a synthetic resin material, more particularly to heating of a thermosetting resin such as an epoxy resin or phenol resin.
2. Description of the Related Art
In molding of a plastic, in general the material is heated to make it plastic and then is injected into a mold etc. to impart a desired shape. For example, in the related art such as shown in FIG. 1 and in Unexamined Patent Publication No. 2009-250474, there is known the technique of placing an object to be heated between parallel electrodes and applying a high frequency wave to the electrodes for causing dielectric heating. Further, there is also generally known the technique of converting a microwave which is generated by a magnetron into a standing wave by using a waveguide, placing the object to be heated inside the waveguide, and heating it by dielectric heating. By using such a technique, for example, compared with heating by conduction, the object to be heated can be heated more uniformly and at a higher speed. However, when loading and unloading an object to be heated into and from electrodes or a waveguide, the electrodes as a whole have to be lifted up or part of the waveguide has to be detached to load and unload the object.
Further, in the related art such as shown in FIG. 2, when taking out the heated material from between the electrodes or from inside the waveguide, the handling ability by a robot hand etc. has to be considered. In such a case, in general, the temperature of the object to be heated has to be kept within a temperature range where the object will not deform due to being gripped by the robot hand etc. In a material heating system (high-frequency heating system), the molding apparatus for molding the heated material and the transport apparatus for loading it into the mold (robot hand etc.) usually are installed separated from each other, so time ended up being required from heating to loading it into the mold and therefore there was the problem that the heated object was not stable in temperature.